Steam-driven engine

ABSTRACT

A positive-displacement, steam-driven engine has a generallyelliptical rotor which is mounted on a shaft that is eccentric of a cylindrical chamber. The rotor has an elongated slot which is parallel to its major axis, and that slot accommodates that shaft. The rotor reciprocates along its major axis as it rotates within the cylindrical chamber. Seals are provided between the rotor and the inner surfaces of the cylindrical chamber to enable the engine to operate as a positive-displacement, steam-driven engine.

1Jn1ted States 1310111 11 1 1 1111 0051111 5] Mar. 25, 1975 1 1 STEAM-DRIVEN ENGINE 3,690,791 9/1972 Dieter 418/119 [75] Inventor: Niranjan Kumar Doshi, East St. FOREIGN PATENTS 0 APPLICATIONS Lows 907575 7/1945 France 418/54 [73] Assignee: Nastol Research, Inc., St. Louis, Mo. 1,175,941 8H994 Germany 418/142 126,924 1/1902 Germany 418/54 [22] Filed: Jan. 2, 1973 336,459 l/1904 France r 418/5 715,217 12/1941 Germany 418/54 211 Appl. No.: 320,202

Primary Examiner-John J. Vrablik [52] US. Cl 418/5, 418/54, 418/60, Attorney, Agent, or FirmRogers, Ezell & Eilers 418/119,4l8/122, 251/185 [51] Int. Cl......F01c1/02, F04c 17/02, F0lc 11/00 58 Field of Search 418/5, 54, 122, 142,60, [571 ABSTRACT 418/119; 137/625, 15; 251/185 -A positive-displacement, steam-driven engine has a generally-elliptical rotor which is mounted on a shaft [56] References Cited that is eccentric of a cylindrical chamber. The rotor UNITED STATES PATENTS has an elongated slot which is parallel to its major 496 954 5/1893 popp 4118/54 axis, and that slot accommodates that shaft. The rotor 418/5 reciprocates along its major axis as it rotates within 821,603 5/1906 Artibee 413/122 the cylindrical chamber. Seals are provided between 937,718 10/1909 Risley 1,310,157 7/1919 DeCampo 418/54 the rotor and the inner surfaces of the cylindrical 1,63 ,486 7/ a e 1 4 155/54 chamber to enable the engine to operate as a positive- 1.802,887 4/1931 Feyens 418/54 displacement, steam-driven engine. 2,969,810 l/l96l Dudley ..137/625.15 3,480,203 11/1969 Koch 418/54 1 Claim, 21 Drawing Figures 97 73 ,(5 /2O fig 1 V 72 I/ 6 770 0 Q; 54 f 52 g 48 42 /46 48 O /7\@ 6 N H\\ 1/ PATENTEDHAR25I9Y5 $373,245

SHEET 1 OF 6 F/GJ 77 PATENTED M25 1975 PATENTED MAR 2 5 I975 sumsqge STEAM-DRIVEN ENGINE This invention relates to improvements in steamdriven engines. More particularly, this invention relates to improvements in positive-displacement steam-driven engines.

It is, therefore, an object of the present invention to provide an improved positive-displacement, steamdriven engine.

External combustion engines are preferable to internal combustion engines for a number of reasons. For example, external combustion engines produce substantially lower percentages of pollutants than do internal combustion engines; and external combustion engines can utilize less expensive fuels than can internal combustion engines. Also, external combustion engines operate with less noise than do internal combustion engines. In addition, an external combustion engine can apply driving torque to its output shaft throughout its entire cycle of operation, whereas an internal combustion engine can not. Moreover, an external combustion engine can. develop maximum torque at low speed, has

a higher stalling torque than does an internal combustion engine, and can provide a fairly-constant speedtorque characteristic over low speed ranges whereas an internal combustion engine can not. Consequently, in many situations, it would be desirable to be able to use an external combustion engine rather than an internal combustion engine. Unfortunately, however, turbinetype external combustion engines provide low starting torque values and are efficient only where extremely high fluid pressures can be utilized; and reciprocatingpiston external combustion engines can not directly convert heat energy into rotary motion and, instead, require a connecting rod and crank shaft to do so. Consequently, it would be desirable to provide an external combustion engine which could be operated by relatively-low pressure fluids and which could directly con vert heat energy into rotary motion. The present invention provides such an external combustion engine; and it is, therefore, an object of the presentinvention to provide an external combustion engine which can operate at low fluid pressures and which can directly convert heat energy into rotary motion.

The positive-displacement, steam-driven engine of the present invention has a generally-elliptical rotor which is mounted on a shaft that is eccentric of a cylindrical chamber. The rotor has an elongated slot which is parallel to its major axis, and that slot accommodates that shaft. The rotor reciprocates along its major axis as it rotates within the cylindrical chamber; and, as it does so, it will directly convert heat energy into rotary motion. It is, therefore, an object of the present invention to provide a positive-displacement, steamdriven engine which has a rotor that rotates and reciprocates to directly convert heat energy into rotary motion.

- The axis of the shaft of the positive-displacement steam-driven engine of the present invention is eccentric of the geometric axis of the cylindrical chamber in which the rotor of that'engine is positioned. Where the distance between the axis of that shaft and the geometric center of that cylindrical chamber is approximately one'fifth of the radius of that cylindrical chamber, the geometric center of the rotor will follow a path which is almost a true circle as that rotor rotates and reciprocates within that cylindrical chamber. Such a result is desirable, because it minimizes undesirable acceleration components, and also promotes dynamic stability with consequent reduction in vibration of, and stresses upon, the shaft. Also where the distance between the axis of the shaft and the geometric center of the cylindrical chamber is approximately one-fifth of the radius of that cylindrical chamber, the relationship between the shaft rotation and volume displacement of the engine will closely approach the relationship between the crank angle to that displacement of a conventional steam-driven, reciprocating engine. This is desirable; because it makes it possible to expand the driving fluid very efficiently, and also makes it possible to apply to the making of the engine of the present invention the extensive bulbs know-how which exits with respect to steam-driven, contact wire engines. It is, therefore, an object of the present invention to provide a positivedisplacement, base engine wherein the distance be tween the axis of the shaft operation, that engine and the geometric center of the cylindrical chamber of that engine is approximately one-fifth of the radius of that cylindrical chamber.

Other and further objects and advantages of the present invention should become apparent from an examination of the drawing and accompanying description.

In the drawing and accompanying description two preferred embodiments of the present invention are shown and described but it is to be understood that the drawing and accompanying description are for the purpose of illustration only and do not limit the invention and that the invention will be defined by the appended claims.

BRIEF DESCRIPTION OF THE DRAWING In the drawing,

FIG. 1 is a front elevational view, which is schematic in part, of one preferred embodiment of steam-driven engine that is made in accordance with the principles and teachings of the present invention,

FIG. 2 is an elevational view of the left-hand side of the steamdriven engine of FIG. 1,

FIG. 3 is a sectional view, which is schematic in part, through the steam-driven engine of FIG. 1, and it is taken along the broken plane indicated by the broken line 33 in FIG. 2,

FIG. 4 is a sectional view through the steam-driven engine of FIG. 1, and it is taken along the plane indicated by the line 4-4 in FIG. 3,

FIG. 5 is a perspective view, on a larger scale, of one end of the rotor of the steam-driven engine of FIG. 1, and it shows one of the apex seals and two of the side seals for that rotor,

FIG. 6 is a sectional view, on an even larger scale, through one of the side seals in FIG. 5, and it is taken along the plane indicated by the line 66 in FIG. 5,

FIG. 7 is a perspective view, on the scale of FIG. 5, which shows the apex seal, the lower part of one end of the rotor, and the spring for that seal,

FIG. 8 is a kinematic view of the rotor and of the rotatable valve element of the steam-driven enging of FIG. 1, and it shows that rotor in its zero position,

FIG. 9 is another kinematic view of the rotor and of the movable valve element of the steam-driven engine of FIG. 1, and it shows that rotor displaced about 45 in the clockwise direction from its zero position,

FIG. 10 is a further kinematic view of the rotor and of the rotatable valve element of the steam-driven engine of FIG. 1, and it shows that rotor displaced about 90 in the clockwise direction from its zero position,

FIG. 11 is a still further kinematic view of the rotor and of the rotatable valve element of the steam-driven engine of FIG. 1, and it shows that rotor displaced about 135 in the clockwise direction from its zero position,

FIG. 12 is a perspective view of a portion of a twostage steam-driven engine that is made in accordance with the principles and teachings of the present invention,

FIG. 13 is a vertical section through the cylindrical chambers, the rotors, the shaft, and the intermediate chamber of the two-stage steam-driven engine of FIG. 12,

FIG. 14 is a front elevational view, which is schematic in part, of the two-stage steam-driven engine of FIG. 12,

FIG. 15 is an elevational view, which is schematic in part, of the left-hand side ofthe two-stage steam-driven engine of FIG. 12,

FIG. 16 is a plan view, which is schematic in part, of the two-stage steam-driven engine of FIG. 12,

FIGv 17 is a kinematic view of the rotors and of the rotatable valve elements of the two-stage steam-driven engine of FIG. 12, and it shows the rotor of the first stage in its zero position,

FIG. 18 is another kinematic view of the rotors and of the rotatable valve elements of the two-stage steamdriven engine of FIG. 12, and it shows the rotor of the first stage displaced about 45 in the clockwise direction from its zero position,

FIG. 19 is another kinematic view of the rotors and of the rotatable valve elements of the two-stage steamdriven engine of FIG. 12, and it shows the rotor of the first stage displaced about 90 in the clockwise direction from its zero position,

FIG. 20 is a still further kinematic view of the rotors and of the rotatable valve elements of the two-stage steam-driven engine of FIG. 12, and it shows the rotor of the first stagedisplaced about 135 in the clockwise direction from its zero position, and

FIG. 21 is a perspective view ofa U-shaped apex seal, the lower part of one end of an alternate form of rotor which uses that seal, and the spring for that seal.

DESCRPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1-11 in detail, the numeral 40 generally denotes a right circular chamber which includes an annulus 42 that has a supporting base 44. An annular flange 46 projects radially outwardly from one side of the annulus 42, and an annular flange 48 projects radially outwardly from the opposite side of that annulus. Ports 50 and 52 of suitable form are provided in the wall of the annulus 42; and those ports are located adjacent the horizontal center line of that annulus, and are disposed at opposite sides of the vertical center line of that annulus. A pipe fitting 54 is secured to the annulus 42 so it surrounds the port 50; and a pipe fitting 5.6 is secured to that annulus so it surrounds the port 52. A side plate 58 of circular form is releasably secured to the annular flange 48 by bolt and nut combinations 62; and that side plate is concentric with the annulus 42. That side plate has an opening 63 therein in which a sleeve bearing 60 is mounted; and that opening is located on the vertical center line of the annulus 42 but is located above the horizontal center line of that annulus. As a result, the opening 63 is eccentric of the annulus 42 and ofthe side plate 58. The numeral 64 denotes a side plate of circular form which is releasably secured to the annular flange 46 by bolt and nut com binations 68; and that side plate also is concentric with the annulus 42. That side plate has an opening 69 therein in which a sleeve bearing 66 is mounted; and,

that opening is coaxial with the opening 63 in the side plate 58. As a result, both of the openings 63 and 69 are eccentric of the annulus 42 and of the side plates 58 and 64. I

The sleeve bearings 60 and 66 are coaxial with each other,.but are eccentric of the annulus 42 and of the side plates 58 and 64. Those sleeve bearings define an axis which is normal to the planes of the side plates 58 and 64; and those sleeve bearings receive and rotatably support the outer ends of a shaft 70. Those outer ends are of circular cross section, but the shaft 70 has a central portion 72 of rectangular cross section. As indicated by FIG. 4, that central portion is disposed between the inner faces of the side plates 58 and 64; and the outer portions of the shaft 72 project outwardly beyond the sleeve bearings 60 and 66.

The numeral 74 denotes a valve housing which has a flange 73 that is held solidly against the rear face of the annular flange 48 on the annulus 42 by two of the bolt and nut combinations 62. That housing has a generally cylindrical chamber therein; and an inlet port 76 at the top of that valve housing communicates with that chamber. A pipe, not shown, will have one end thereof secured to the valve housing 74 so it is in communication with the inlet port 76. The numeral 77 denotes a closure for the front of the generally cylindrical chamber within the valve housing 74; and that closure is secured to that valve housing by bolts 78. That closure has an orifice 79 therein and has an outlet port 80 which communicates with the orifice 79. A pipe ell 82 has one end thereof secured to the valve housing 74 so it communicates with the outlet port 80. The closure 77 also has an opening 81 therein which is concentric with the cylindrical chamber in the housing 74.

The numeral 84 denotes a generally disc-like element which is rotatably mounted within the cylindrical chamber in the valve housing 74; and that element is located immediately adjacent the inner surface of the closure 77. That element has a notch 85 therein which has the sides thereof defined by radii; and the configuration of that notch is similar to the configuration of the orifice 79. As shown particularly by FIG. 3, the angular span of the notch 85 isslightly greater than the angular span of the orifice 79. The numeral 86 denotes a generally-cylindrical boss at the inner face of the element 84; and that boss has an inwardly-extending, reduced-diameter portion 87. The numeral 88 denotes a cylindrical guide which is provided within the cylindrical chamber in the valve housing 74, and that guide is coaxial with the rotatable valve element 84, with the boss 86, and with the reduced-diameter portion 87. A helical compression spring 90 has one end thereof telescoped over the guide 88 and has the other end thereof telescoped over the reduced-diameter portion 87 of boss 86; and hence that spring is held in coaxial alignment with the rotatable element 84. That spring urges the outer face of the element 84 against the inner face of the closure 77, and thereby keeps steam from leaking between those faces.

The numeral 92 denotes a shaft which is journalled within the opening 81 in the closure 77 of the valve housing 74; and the inner end of that shaft has a bladelike portion 93 which fits within a slot in the boss 86 on the element 84. That blade-like portion and that slot will force the rotatable element 84 to rotate with the shaft 92. The numeral 94 denotes a sprocket gear which is mounted on the outer end of the shaft 92, and that sprocket gear can be rotated to cause rotation of the element 84 within the valve housing 74. The numeral 96 denotes a sprocket gear which is mounted on the outer end of the shaft 70, and that sprocket gear will be rotated by that shaft. A sprocket chain, not shown, will extend around and mesh with the teeth on the sprocket gears 94 and 96. The sprocket gear 96 is sufficiently larger than the sprocket gear 94 to cause the shaft 92 to make two revolutions each time the shaft 70 makes one revolution.

The numeral 100 denotes a housing for a directional control for the steam-driven engine shown in FIGS. 1-11; and that housing has ports 102, 104, 106 and 108. Pipe ells 109, 110 and 112 are secured to the housing 100 so they surround the ports 102, 104 and 108, respectively; and a pipe fitting 114 is secured to the housing 100 so it surrounds the port 106. A pipe 116 extends from the pipe ell 82 to a pipe tee 115; and a pipe 117 extends from the outlet port of that pipe tee to the pipe ell 109. A manually-operated valve 119 has the inlet port thereof connected to the pipe, not shown, which is connected to the port 76; and it has the outlet port thereof connected to the upper port of the pipe tee 115. A pipe 118 extends from the pipe ell 110 to the pipe fitting 56 on the annulus 42; and a pipe 120 extends from the pipe fitting 54 on that annulus to the pipe ell 112. A pipe 121 extends from the pipe fitting 114 to a condenser, not shown, where the steam from the housing 100 will be condensed to water, and can then be forced by a feed pump into the boiler, not shown. The valve 119, the pipe tee 115, the pipes 116 and 117, and the major portions of the lengths of the pipes 118 and 120 are shown schematically in FIGS. 1 and 3.

The numeral 122 denotes a rotor which is mounted within the housing 100; and that rotor has passages 124 and 126 therein. Whenever the rotor is in the position shown by FIG. 3, the passage 124 will interconnect the ports 102 and 104, and the passage 126 will interconnect the ports 108 and 106. However, whenever the rotor 122 is rotated approximately ninety degrees in the clockwise direction from the position shown by FIG. 3, the passage 124 will interconnect the port 104 with the port 106 and will interconnect the port 102 with the port 108. That rotor can be rotated between the position shown by FIG. 3 and a position which is displaced ninety degrees in the clockwise direction from that position by manual operation of a handle 128 and a shaft 129.

The numeral 130 generally denotes a rotor which is disposed within the cylindrical chamber 40; and that rotor is generally elliptical in side elevation. That rotor is formed from a cylindrical segment 132 which is less than one-half of a cylinder and by a second cylindrical segment 134 which also is less than one-half of a cylinder. Notches 136 and 138, respectively, in the cylindrical segments 132 and 134 define an elongated rectangular slot 136, 138 within the rotor 130. That slot accommodates the central portion 72 of the shaft 70; and

two of the opposed faces of that central portion slide against the elongated faces of the slot 136, 138. However, that slot is long enough to keep either end thereof from engaging the central portion 72 of the shaft 70. The numeral 140 denotes a shallow notch adjacent one end of the cylindrical segment 132, and the numeral 142 denotes a similar notchat the corresponding end ofthe cylindrical segment 134; and those notches coact to define an open-ended slot 140, 142 at one end of the major axis of the rotor 130. The numeral 146 denotes a shallow notch at the opposite end of the cylindrical segment 132, and the numeral 148 denotes a similar notch at the corresponding end of the cylindrical segment 134; and those notches coact to define an openended slot 146, 148 at the opposite end of the major axis of the rotor 130.

The numeral 150 denotes an arcuate groove of rectangular cross section in the cylindrical segment 132; and one end of that groove communicates with the slot 140, 142, while the other end of that groove communicates with the slot 146, 148, as shown by FIG. 5. The numeral 152 denotes an arcuate groove of rectangular cross section in the cylindrical segment 134; and one end of that groove communicates with the slot 140, 142, while the other end of that groove communicates with the slot 146, 148, as shown by FIG. 5. The arcuate grooves 150 and 152 coact to define a generally elliptical groove 150, 152 in the left-hand face of the rotor 130 as that rotor is viewed in FIG. 4. The numeral 154 denotes an arcuate groove of rectangular cross section in the cylindrical segment 132; and one end of that groove communicates with the slot 140, 142, while the other end of that groove communicates with the slot 146, 148. The numeral 156 denotes an arcuate groove of rectangular cross section in the cylindrical segment 134; and one end of that groove communicates with the slot 140, 142, while the other end of that groove communicates with the slot 146, 148. The grooves 154 and 156 coact to define a generally elliptical groove 154, I56 in the right-hand face of the rotor 130 as that rotor is viewed in FIG. 4.

The numeral 158 denotes an arcuate metal seal of rectangular cross section which is disposed within the arcuate groove 150 in the cylindrical segment 132; and the numeral 159 denotes a similar arcuate metal seal which is disposed within the arcuate groove 152 in the cylindrical segment 134. Helical compression springs 157 underlie the arcuate metal seals 158 and 159, and those springs have the inner ends thereof seated within sockets which extend axially-inwardly from the arcuate grooves 150 and 152, as shown by FIG. 6. Those helical compression springs urge the outer faces of the arcuate metal seals 158 and 159 against the inner face of the side plate 64. The numeral 160 denotes an arcuate metal seal of rectangular cross section which is disposed within the arcuate groove 154 in the cylindrical segment 132; and the numeral 161 denotes a similar arcuate metal seal which is disposed within the arcuate groove 156 in the cylindrical segment 134. Helical compression springs, not shown, underlie those arcuate metal seals and have the inner ends thereof disposed within sockets which extend axially-inwardly from the arcuate grooves 154 and 156. Those helical compression springs urge the outer faces of the arcuate metal seals 160 and 161 into sealing engagement with the inner face of the side plate 58.

The numeral 162 denotes an annular groove of rectangular cross section in the left-hand faces of the cylindrical segments 132 and 134 as those segments are viewed in FIG. 4; and the numeral 164 denotes an annular groove of rectangular cross section in the righthand faces of those cylindrical segments. An annular metal seal 166 of rectangular cross section is disposed within the annular groove 162; and helical compression springs, not shown, underlie that annular metal seal. The inner ends of those helical compression springs extend into sockets which extend axially-inwardly from the annular groove 162. Those helical compression springs urge the outer face of the annular metal seal 166 into sealing engagement with the inner face of the side plate 64. The numeral 168 denotes an annular metal seal of rectangular cross section which is disposed within the annular groove 164; and helical compression springs, not shown, underlie that annular metal seal. The inner ends of those helical compression springs extend into sockets which extend axiallyinwardly from the annular groove 164. Those helical compression springs urge the outer face of the annular metal seal 168 into sealing engagement with the inner face of the side plate 58.

The numeral 169 denotes a rectangular metal seal which is disposed within the groove 140, 142 in the rotor 130; and a bowed leaf spring, not shown, underlies that metal seal. That spring urges the outer surface of that metal seal into sealing engagement with the inner surface of the annulus 42. The metal seal 169 is made long enough so the end faces thereof abut the inner faces of the side plates 58 and 64 in sealing engagements. The numeral 171 denotes a rectangular metal seal which is disposed within the groove 146, 148 in the rotor 130; and a bowed leaf spring 173 underlies that metal seal. That spring urges the outer surface of that metal seal into sealing engagement with the inner surface of the annulus 42. The metal seal 171 is made long enough so the end faces thereof abut the inner faces of the side plates 58 and 64 in sealing engagements.

Bolt and nut combinations 170 fixedly secure together the cylindrical segments 132 and 134, of the rotor 130, so they will rotate as a unit. Appropriate sockets are formed in the cylindrical segments 132 and 134 for the heads of the bolts and for the nuts of the bolt and nut combinations 170, as shown particularly by FIG. 3.

The outer periphery of the cylindrical segment 132 has a radius which is just slightly less than the radius of the inner surface of the annulus 42; and, similarly, the outer periphery of the cylindrical segment 134 has a radius which is just slightly less than the radius of that inner surface. In the preferred embodiment of steamdriven engine of FIGS. 1-11, the distance between the axis of the shaft 70 and the geometric axis of the annulus 42 is substantially one-fifth of the radius of the inner surface of that annulus. The length of the major axis of the rotor 130 is 2/5 V 24R, and the length of the inner axis of that rotor is 8/5 R, where R is the radius of the inner surface of the annulus 42. Also in that preferred embodiment, an oil pump will supply oil to a passage, not shown, in the shaft which communicates with the slot 136, 138. The resulting supply of oil will reduce friction and wear between the faces of that shaft and the elongated faces of that slot. The metal seals 166 and 168 will coact with the inner faces of the side plates 64 and 58, respectively, to prevent the escape of that oil past the rotor 130.

Whenever the rotor 130 is in the zero position shown by FIG. 8, the periphery of the cylindrical segment 134 will be immediately adjacent the upper portion of the inner surface of the annulus 42, as shown by FIG. 8. At such time, the center of the rotor 130 and the axis of the shaft will be co-axial. Also, at such time. the metal seal 169 will be immediately above the port 50, and the metal seal 171 will be immediately below the port 52; and the right-hand end of the cylindrical segment 134 will be in register with the port 52. In addition, at such time, the rotatable element 84 within the valve housing 74 will be in the position shown by FIG. 8. If the steam-driven engine is being started, the valve 119 will be open; and hence steam will pass through that valve, and also through the valve housing 74, to the housing of the directional control. That steam then will pass to the port 52, where it will exert a pressure against the right-hand end of the rotor which will urge that rotor to start rotating in the clockwise direction.

As that rotor so rotates, the cylindrical segments 132 and 134 of the rotor will be forced to progressively shift downwardly and to the right toward the position shown by FIG. 9. As those cylindrical segments so shift, the distance between the center of the rotor 130 and the axis of the shaft will increase progressively, and will thereby progressively increase the effective rotative moment which the steam causes that rotor to apply to that shaft. By the time the rotor 130 has shifted downwardly and to the right to the position of FIG. 9, the distance between the center of the rotor 130 and the axis of the shaft 70 will be close to its maximum value; and the moment arm of the force which the steam causes that rotor to apply to that shaft will be close to its maxi mum value.

Shortly after the rotor 130 rotates beyond the position shown by FIG. 9, the notch 85 in the rotatable element 84 will move out of register with the orifice 79; and then that rotatable element will prevent any further flow of steam through the pipe 116. However, the valve 119, the pipe tee 115, the pipe 117, the directional control, and the pipe 118 will continue to supply steam to the port 52; and that steam will cause the rotor 130 to continue to rotate the shaft in the clockwise position. This means that the cylindrical segments 132 and 134 of the rotor 130 will continue to move downwardly; and, at the time that rotor reaches the position of FIG. 10, the distance between the center of the rotor 130 and the axis of the shaft will be at its maximum value,

and hence the moment arm of the force which steam causes that rotor to apply to that shaft will be at its maximum value.

Steam will continue to flow to the port 52 via valve 119, the pipe tee 115, the pipe 117, the directional con trol, and the pipe 118; and that steam will cause the rotor 130 to continue to rotate the shaft in the clockwise position. This means that the cylindrical segments 132 and 134 of the rotor 130 will start moving upwardly and to the left toward the position of FIG. 11. As those cylindrical segments so move, the distance between the center of the rotor I30 and the axis of the shaft will decrease progressively; and hence the moment arm of the force which the steam causes the rotor to apply to that shaft will be decreased progressively. However, at the time the rotor 130 reaches the position of FIG. 11, the distance between the center of the rotor 130 and the axis of the shaft will be only slightly less than its maximum value.

Further steam will enter the port 52, and will force the rotor 130 to continue to rotate the shaft in the clockwise direction. As that rotor moves from the position of FIG. 11 toward its one hundred and eighty degree position, that rotor will continue to shift upwardly and to the left; and the continued shift of that rotor will progressively decrease the distance between the center of that rotor and the axis of that shaft. At the time the rotor 130 moves into its one hundred and eighty degree position, the center of the rotor 130 and the axis of the shaft will be coaxial. Also, at that time, the periphery of the cylindrical segment 132 will be immediately adjacent the upper portion of the inner surface of the annulus 42. Further, the metal seal 171 will be immediately above the port 50 and the metal seal169 will be immediately below the port 52; and the right-hand end of the cylindrical segment 132 will be in register with the port 52. In addition, at such time, the rotatable element 84 within the valve housing 74 will be in the position shown by FIG. 8. As the rotor 130 moves into its one hundred and eighty degree position, the metal seal 171 will uncover the port 50; and, thereupon, the steam within the cylindrical chamber 40 will pass through the pipe 120, the pipe fitting 112, the passage 126 in the directional control, and the pipe fitting 114 and pipe 12] to the condenser.

During the rotation of the rotor 130 from the zero position to FIG. 8 to its 180 position, the shaft rotated l80 but the rotatable element 84 rotated 360. Consequently, when the rotor 130 is in its 180 position, the rotatable element 84 will be in the position of FIG. 8; and thus will be supplying steam to the port 52. That steam, plus the steam supplied by valve 119, pipe tee 115, pipe 117, the directional control, and the pipe 118, will cause the rotor 130 to progressively rotate in the clockwise direction from its 180 position to the position of FIG. 8. As that rotor so rotates, the shaft will rotate 180 but the rotatable element 84 will rotate 360. This means that during one complete revolution of the rotor 130, the shaft 70 will make one complete revolution but the rotatable element 84 will make two complete revolutions.

It will be noted that steam was caused to continuously apply propulsive forces to the rotor 130 throughout the entire revolution of that rotor; and this contrasts favorably with the application of propulsive forces to the piston of an internal combustion engine during only one-halfor one-quarter of each cycle of operation. Also, it will be noted that the rotor 130 directly converted steam energy into rotary motion; and this contrasts favorably with the usual steam engine which requires a crank arm and connecting rod to convert steam energy into rotary motion. In addition, it will be noted that the metal seals 158, 159, 160, 161, 169 and 171 effectively kept the steam from leaking past them; and thereby kept that steam from leaking from the high pressure side to the low pressure side of the cylindrical chamber 40. Consequently, the steam-driven engine of FIGS. 1-11 operates as a positive-displacement, steamdriven engine; and this contrasts favorably with the op eration of a steam turbine.

As the rotor 130 rotates within the cylindrical chamber 40, the outer faces of the metal seals 169 and 171 will engage differentportions of the inner surface of the annulus 42. That engagement will cause relative movement between the metal seal 169 and the open-ended slot 140, 142, and also will cause relative movement between the metal seal 171 and the open-ended slot 146, I48; and the bowed leaf spring 173 and its counterpart will accommodate such relative movement. lmportantly, that bowed leaf spring and its counterpart will keep the outer face of each of those seals in continuous, yielding engagement with the inner surface of that annulus during the rotation of the rotor 130 thereby preventing leakage of steam between the high and low pressure areas within the cylindrical chamber 40, and also cushioning the radial shifting of the rotor 130 relative to the shaft 70. As a result, the radial shifting of the rotor 130 is a controlled shifting rather than an abrupt shifting; and that rotor is not subjected to impact forces.

At the beginning of the hereinbefore-described revolution of the rotor 130, the center of that rotor was coaxial with the axis of the shaft and, at the end of one-half of that revolution, the center of that rotor again was coaxial with the axis of that shaft. However, during the first of that one-half revolution, the center of the rotor moved to the right, moved downwardly and to the right, and moved downwardly relative to the axis of the shaft 70; and during the last 90 of that one-half revolution, the center of that rotor moved upwardly, moved upwardly and to the left, and moved to the left relative to that axis. During the next one-half revolution, the center of the rotor 1 30 again moved to the right, moved downardly and to the right, moved downwardly, moved upwardly, moved upwardly and to the left, and moved to the left relative to the axis of the shaft 70. As the center of that rotor moved relative to the axis of that shaft, during each of those onehalf revolutions, that center followed an arcuate path which was essentially circular. The movement of the center of the rotor 130 through such an essentially circular path is desirable; because it minimizes the acceleration and deceleration components of force, and also minimizes vibrational components. Where the distance between the geometric center of the annulus 42 and the axis of the shaft 70 is exactly one-fifth of the radius of the inner surface of that annulus, the arcuate path which the center of the rotor 130 follows during each half-revolution of that rotor will be almost a true circle. Specifically, the maximum deviation of the arcuate path of the center of the rotor 130 from a true circular path will be no more than four-hundredths of the radius of the inner surface of the annulus 42. As a result, the preferred embodiment of steam-driven engine shown in FIGS. 1-11 operates smoothly and with minimum vibration.

Where larger deviations, of the arcuate path of center of the rotor 130 from a true circular path, are acceptable, a distance other than one-fifth of the radius of the inner surface of the annulus 42 can be provided between the geometric center of that annulus and the axis of the shaft 70. However, the distance between that geometric center and that axis should not exceed one-third, and should not be less than one-tenth, of the radius of that inner surface.

If desired, the inner surface of the annulus 42 could be machined so it would precisely accommodate the slightly acircular rotation of the rotor 130. However, because ofthe deviation, of the arcuate path of the center of the rotor 130 from a true circle, is very small, the

annulus 42 can have the inner-surface thereof machined as a true cylindrical surface. The deviation of the arcuate path of the center of the rotor 130 from a true circle is adequately compensated for by the axial movement of the seals 169 and 171 relative to the major axis of that rotor.

As the rotatable element 84 and the valve 119 continue to supply steam to the port 52, the rotor 130 will continue to rotate in the clockwise direction; and that rotor will rotate at a progressively-increasing rate of speed. When the speed of that rotor approaches a predetermined value, a'governor, not shown, of standard and usual form will coact with a throttling valve, not shown, to reduce the amount of steam which is supplied to the valve housing 74 and to the valve 119. Consequently, that governor will coact with that throttling valve to limit the rate of rotation of the rotor 130.

Shortly before or after the rotor 130 attains its desired speed, the valve 119 will be closed; and, thereafter, during each half-revolution of the rotor 130, steam will be supplied to the port 52 during only about onethird ofthat half-revolution. However, the steam which is supplied to that port during that one-third of that half-revolution will expand, and will continue to apply propulsive forces to the rotor 130, during the rest of that half-revolution. In this way, the embodiment of steam-driven engine of FIGS. l1l takes full advantage of the expansion characteristics of the steam which is supplied to the port 52. The valve 119 can then be left closed as long as the steam-driven engine of FIGS. 1-11 is operated in the forward direction; but, when that engine is stopped or has the direction of rotation thereof reversed, the valve 119 will be re-opened during the subsequent starting of that steam-driven engine. To stop the steam-driven engine of FIGS. 1-11, it is only necessary to halt the flow of steam to the port 52; and, thereupon, the rotor 130 will coast to a stop.

The rotor 130, of the steam-driven engine shown in FIGS. 1-11 can be caused to rotate in the opposite direction by shifting the handle 128 of the directional control to dispose the passage 124 in register with the ports I04 and 106 and to dispose the passage 126 in register with the ports 102 and 108. At such time, steam will be supplied to the port 50 rather than to the port 52; and spent steam will pass from the port 52 via the housing 100 of the directional control to the pipe 121, and thence to the condenser, not shown. Ifit is assumed that the rotor 130 is in a position wich is displaced a few degrees in the counterclockwise direction from the position of FIG. 8, steam entering the port 50 will apply a downward force to the left-hand end of that rotor; and that force will start that rotor rotating in the counterclockwise direction. The rotor will successively move to the left, move downwardly and to the left, move downwardly, move upwardly, move upwardly and to the right, and move to the right during each halfrevolution thereof. The rotatable element 84 will rotate in the counterclockwise direction, and it will rotate at twice the rate of rotation ofthe rotor 130. During onesixth of each half-revolution of the rotor 130, the rotatable element 84 will supply steam to the port 50; but, during the initial rotation of that rotor in the counterclockwise direction, the valve 119 will continuously supply steam to that port. Even after the rotor 130 attains its desired speed, the valve 119 will be left open, at least in part, to supply steam to the port 50.

Referring particularly to FIGS. 12-20, the numeral generally denotes a right-circular chamber which can be essentially identical to the chamber 40 of the embodiment of FIGS. l-ll. The numeral 182 denotes a right-circular chamber which is immediately adjacent to the chamber 180, as shown particularly by FIGS. 12, l3, l5 and 16. The diameter of the chamber 182 is larger than the diameter of the chamber 180; and, in the preferred embodiment shown in FIGS. 12-20, the inner diameter of the chamber 182 is 50 percent larger than the inner diameter of the chamber 180.

The numeral 184 denotes an annulus which is part of the chamber 180; and that annulus has a base 186 in which an elongated cylindrical chamber 192 is incorporated. The annulus 184 is a radially-extending annular.

flange at one side thereof, and has a radiallyextending annular flange 187 at the other side thereof. As shown particularly by FIG. 13, the annular flange 185 has a larger radial span than does the annular flange 187. The numeral 188 denotes an annulus which is part of the chamber 182; and that annulus has a base 190. The annulus 188 has a radially-extending annular flange 189 at one side thereof, and has a radiallyextending annular flange 191 at the other side thereof. The annular flange 187 is concentric with the annulus 184, and the annular flanges 189 and 191 are concentric with the annulus 188; but, the annular flange 185 is concentric with the annulus 188 rather than with the annulus 184, as indicated particularly by FIG. 13.

The numeral 194 denotes a disc-like closure for the left-hand end of the cylindrical chamber 192 which is incorporated within the base 186 of the chamber 180. The numeral 196 denotes a disclike closure for the right-hand end of that cylindrical chamber. Those disc'- Iike closures are circular and are releasably secured to the cylindrical chamber 192 by bolt and nut combinations, as indicated by FIGS. 14 and 15. The numeral 193 denotes a circular side plate which is secured to the annularflange 189 by bolt and nut combinations, the numeral 195 denotes a center plate which is interposed between the annular flanges 191 and 185, and the numeral 197 denotes a side plate which is well secured to the annular flange 187 by nut and bolt combinations. Nut and bolt combinations hold the annular flanges 191 and 185 in assembled engagement with the center plate 195, as shown particularly by FIG. 13.

The numeral 200 denotes a safety valve which is mounted on, and which communicates the interior of, the cylindrical chamber 192; and that valve can vent to the atmosphere adjacent the chamber 180. The valve will normally be closed; but it will open whenever the pressure within that cylindrical chamber rises to a value within 10 to 15 pounds per square inch of the maximum pressure on the steam which is supplied to the chamber 180. As a result, the valve 200 makes certain that a pressure differential can be developed and maintained between the inlet and outlet ports of the chamber 180.

The numeral 198 denotes a valve housing which is suitably secured to the annular flange 187 by two of the bolt and nut combinations that hold the side plate 197 in assembled relation with that annular flange. The valve housng 198 can be identical to the valve housing 74 of the steam-driven engine shown in FIGS. 111. A rotatable element 204 is rotatably mounted within the valve housing 198, and that element has a notch 206 therein. That notch can selectively move into and out of register with an outlet orifice 208 in the closure of the valve housing 198. The numeral 207 denotes the inlet port for that valve housing; and the numeral 210 denotes the outlet port for that valve housing. A shaft 212 is rotatably secured to the rotatable element 204; and the front end of that shaft extends forwardly of the closure of the valve housing 198. A sprocket gear 214 is secured to the foreward end of that shaft; and that sprocket gear is rotatable to rotate the element 204.

The numeral 216 denotes a second valve housing which is suitably secured to the annular flange 187 by two of the nut and bolt combinations that hold the side plate 197 in assembled relation with that annular flange. Because of the space limitations in the drawing, the size of the valve housing 216 is shown as being the same as the size of the valve housing 198; but, in actual practice, the valve housing 216 will be substantially larger than the valve housing 198. A rotatable element 220, which has a notch 222 in the periphery thereof, is rotatably mounted within the valve housing 216. Thar rotatable element is rotatable adjacent an outlet orifice 224 in the closure of that valve housing; and the orifice communicates with the outlet 226 of that valve housing. The numeral 223 denotes the inlet port of the valve housing 216. A shaft 228 is rotatably journalled within the closure for the valve housing 216; and that shaft has the inner end thereof fixedly secured to the rotatable element 220. A sprocket gear 230 is fixedly secured to the forward end of that rotatable shaft; and, as indicated particularly by FIG. 16, the sprocket gears 214 and 230 are coplanar.

The numeral 234 denotes a housing for the directional control which is associated with the cylindrical chamber 180; and that housing can be identical to the directional control housing 100 shown in FIGS. 1-11. A pipe 236 is connected to the inlet port 207 of the valve housing 198 and also to the inlet port of a valve 237, as indicated by FIG. 16. The outlet of the valve 237 is connected to one inlet port ofa pipe tee 239; and the other inlet port of that pipe tee is connected to the outlet port 210 of the valve housing 198. The outlet port of the pipe tee 239 is connected to the one of the ports of the directional control housing 234 by a pipe 238. A second of the ports of the directional control housing 234 is connected to port 262 of the cylindrical chamber 180 by a pipe 240. A pipe 241 extends from port 260 of the cylindrical chamber 180 to a third port of the directional control housing 234; and a pipe 242 extends from the fourth port of the directional control housing 234 to the closure 196 for the intermediate chamber 192 which is located within the base 186.

A pipe 246 extends from the closure 194 of that intermediate chamber to the inlet port 223 of the valve housing 216. A pipe 248 extends from the outlet port 226 of the valve housing to one of the four ports of a directional control housing 244. A pipe 250 extends from a second port of the directional control housing 244 to port 266 of the cylindrical chamber 182. A pipe 252 extends from port 264 of that cylindrical chamber to a third port of the directional control housing 244. A pipe 254 extends from the fourth port of the directional control housing 244 to a condenser, not shown, which will condense the steam to water. rotor, not shown, which is similar to the rotor 122 within the directional control housing 100 in FIG. 3, is mounted within the directional control housing 234. Also, a rotor, not shown, which is similar to the rotor 122 in FIG.

3, is mounted within the directional control housing 244. Those rotors are connected together and are connected to a handle 256, so rotation of that handle can provide simultaneous rotation of those rotors. Because of the space limitations of the drawing, the size of the directional control housing 244 is shown as being the same as the size of the directional control housing 234; but, in actual practice, the directional control housing 244 will be substantially larger than the directional control housing 234.

A rotor 274, which can be identical to the rotor of the stem-driven engine of FIGS. 1-11, is rotatably mounted within the cylindrical chamber 180. That rotor includes a cylindrical segment 270 which can be identical to the cylindrical segment 134, and also includes a cylindrical segment 272 which can be identical to the cylindrical segment 132. Those cylindrical segments have notches in the confronting faces thereof which coact to define an elongated rectangular slot that accommodates a portion 284 of a shaft 282 which is supported by sleeve-type bearings that are mounted within the openings in the plates 193, and 197, as shown particularly by FIG. 13. The numeral 280 denotes a rotor which is similar to, but which is larger than, the rotor 274; and the rotor 280 is rotatably disposed within the cylindrical chamber 182. That rotor includes a cylindrical segment 276 which is similar to, but larger than, the cylindrical segment 270; and also includes a cylindrical segment 278 which is similar to, but larger than, the cylindrical segment 272. The cylindrical segments 276 and 278 have notches in the confronting faces thereof which coact to define an elongated rectangular slot that accommodates a portion 286 of the shaft 282. The portions 284 and. 286 of that shaft are square in cross section; but the faces of the portion 286 are wider than the faces of the portion 284. The flat faces of the square portions 284 and 286 of the shaft 282 are parallel to each other; but the elongated rectangular slots in the rotors 274 and 280 have the major axes thereof angularly displaced from each other by ninety degrees, as indicated particularly by FIGS. 1720.

A sprocket gear 288 is fixedly secured to the front of the shaft 282; and that sprocket gear is coplanar with the sprocket gears 214 and 230 which are mounted, respectively, on the shafts 212 and 228. A sprocket chain, not shown, will engage the teeth on all of the sprocket gears 214, 230 and 288; and thus will enable rotation of the sprocket gear 288 to cause rotation of the sprocket gears 214 and 230. The effective diameter of the sprocket gear 288 is twice the effective diameter of the sprocket gear 214, and also in twice the effective diameter of the sprocket gear 230. As a result, each of the sprocket gears 214 and 230 will make two complete revolutions while the sprocket gear 288 is making one complete revolution.

As indicated particularly by FIG. 13, the rotor 274 has grooves in the left-hand face thereof, and also has grooves in the right-hand face thereof. The grooves in the left-hand face of that rotor can be identical to the grooves 150, 152 and 162 in the left-hand face of the rotor 130 in FIG. 4; and the grooves in the right-hand face of the rotor 274 can be identical to the grooves 154, 156 and 164 in the right-hand face of the rotor 130. Metal seals are disposed within the grooves in the left-hand and right-hand faces of the rotor 274; and the metal seals within the grooves in the left-hand face of that rotor can be identical to the metal seals 158, 159 and 166 within the grooves in the left-hand face of the rotor 130, while the metal seals within the grooves in the right-hand face of the rotor 274 can be identical to the metal seals 160, 161 and 168 within the grooves in the right-hand face of the rotor 130. Helical compression springs, not shown, which are comparable to the helical compression springs 157 in FIG. 6, are disposed within sockets that are contigous to the grooves in the left-hand and right-hand faces of the rotor 274; and those helical compression springs will urge the various metal seals within those grooves into sealing engagement with the confronting faces of center plate 195 and side plate 197.

The rotor 280 has grooves in the left-hand and righthand faces thereof, as shown by FIG. 13; and these grooves can be similar to, but larger than, the grooves in the left-hand and right-hand faces of the rotor 274. Metal seals are disposed within the grooves in the lefthand and right-hand faces of the rotor 280; and those metals can be similar to, but larger than, the metal seals which are disposed within the grooves in the left-hand and right-hand faces of the rotor 274. Helical compression springs, not shown, which can be similar to, but larger than, the helical compression springs 157 of FIG. 6 are disposed within sockets that are contiguous to the grooves in the left-hand and right-hand faces of the rotor 280; and those helical compression springs will urge the various metal seals within those grooves into sealing engagement with the confronting faces of side plate 193 and center plate 195.

Open-ended slots, not shown, are provided in the rotors 274 and 280 at the ends of the major axes of those rotors; and those open-ended slots accommodate seals and springs which are comparable to the seal 171 and the bowed leaf spring 173 of FIG. 7. Further, a passage, not shown, is provided in the shaft 282 which will conduct oil to one of the inactive faces of the square portion 284 of that shaft, and also to one of the inactive faces of the square portion 286 of that shaft. That passage will supply oil to the rectangular slots within the rotors 274 and 280; and that oil will minimize friction and wear between the elongated sides of those slots and the square-faced portions 284 and 286 of the shaft 282. The metal seals within the innermost grooves of the rotors 274 and 280 will confine that oil and prevent its escape outwardly of those rotors. I

The shaft 282 is concentric throughout the length thereof; although the portions 284 and 286 have square cross sections, whereas the central portion and the outer portions have circular cross sections. Because that shaft is concentric throughout the length thereof, the shaft-receiving openings in the side plates 193 and 197 are concentric with the shaft-receiving opening in the center plate 195. Both cylindrical chambers 180 and 182 are eccentric of the axis of the shaft 282; but, because the cylindrical chamber 182 is larger than the cylindrical chamber 180, the geometric center of cylindrical chamber 182 is more eccentric of the axis of shaft 282 than is the geometric center of cylindrical chamber 180. If the inner diameter of the annulus 184 is eighhunits and the inner diameter of the annulus 188 is 12 units, the geometric center of the inner surface of the annulus 188 will be four-tenths of a unit more eccentric of the axis of the shaft 282 than will be the geometric center of the inner surface of the annulus 184. To accommodate the greater eccentricity of the geometric center of the inner surface of the annulus 188. the rectangular slot within the rotor 280-is made longer than the rectangular slot within the rotor 274.

When the rotor 274 is in its zero position, as shown by FIG. 17, the rotor 280 will be displaced ninety degrees in the clockwise direction from its zero position. At that time, the right-hand end of the cylindrical segment 270 will be blocking the port 262 but the lefthand end of the cylindrical segment 272 will leave the port 260 open. Also, at that time, the center of the rotor 274 and the axis of the shaft 282 will be coaxial. The center of the rotor 280 will, however, be displaced below the axis of the shaft 282 a distance equal to the maximum distance which the center of that rotor can be displaced from that axis. Because the center of the rotor 274 is coaxial with the axis of the shaft 282, the moment of force, which steam that is supplied to the port 262 can apply to that rotor, will be a minimum. However, because the center of the rotor 280 is displaced as far as it can be from the axis of the shaft 282, the moment of the force, which steam that is supplied to the port.266 can apply to that rotor, will be a maximum.

After the shaft 282 has rotated about forty-five degrees in the clockwise direction from the zero position of FIG. 17, the rotors 274 and 280 will move into the positions shown by FIG. 18. As that shaft rotates through those 45, the rotor 274 will shift downwardly and to the right, but the rotor 280 will shift upwardly and to the left. At the time the shaft 282 reaches the position indicated by FIG. 18, the center of the rotor 274 will be displaced a substantial distance from the axis of the shaft 282, but the center of the rotor 280 will be closer to the axis of that shaft than it was in FIG. 17.

After the shaft 282 has rotated an additional fortyfive degrees in the clockwise direction to reach the position of FIG. 19, the center of the rotor 280 will be coaxial with the axis of the shaft 282, but the center of the rotor 274 will be as distant from the axis of that shaft as it can be. At such time, the moment arm which steam, that is supplied to the port 262, can apply to the rotor 274 will be a maximum, but the moment arm which steam, supplied to the port 266, can apply to the rotor 280 will be a minimum.

All of this means that as the rotors 274 and 280 rotate, respectively, within the cylindrical chambers and 182, the moment arms of the forces which steam applied to those rotors will vary from instant to instant. Importantly, whenever the moment arm of the force which steam applies to one of those rotors is a minimum, the moment arm of the force which steam applies to the other of those rotors is a maximum. This is desirable; because it tends to balance the effective values of the forces which steam applies to those rotors.

Whenever the rotor 274 is in the zero position shown by FIG. 17, the rotatable element 204 within the valve housing 198 will have the notch 206 therein partially exposing the upper end of the outlet orifice 208; and hence steam will pass through that outlet orifice to the port 262. Also at that time, the major axis of the rotor 280 will be vertical, and notch 222 in the rotatable element 220 within the valve housing 216 will be dis.

placed from the outlet orifice 224; and hence steam will not pass through that valve housing to the port 266. If the steam-driven engine is being started and has not gotten up to speed, the valve 237 will be open; and hence steam will pass through that valve, as well as through the valve housing 198, to the port 262 via the directional control housing 234. That steam will exert pressure against the rotor 274 and urge that rotor to rotate in the clockwise direction.

When the rotor 274 is in the position of FIG. 18, the notch 206 in the rotatable element 204 within the valve housing 198 will be exposing part of the lower end of the outlet orifice 208; but the notch 222 in the rotatable element 220 will still be displaced from the outlet orifice 224 in the valve housing 216. This means that steam will continue to be supplied to the port 262 by valve housing 198 and by valve 237, but that no steam will be supplied to the port 266.

Shortly after the rotor 274 rotates beyond the position shown in FIG. 18, the notch 206 in the rotatable element 204 will move out of register with the outlet orifice 208; and, thereupon, that rotatable element will prevent further flow of steam through the pipe which extends to the pipe tee 239. However, the valve 237, that pipe tee, the pipe 238, the rotor within the directional control housing 234, and the pipe 240 will continue to supply steam to the port 262. The notch 222 in the rotatable element 220 will still be out of register with the outlet orifice 224; and hence neither of the valve housings 198 and 216 will be supplying steam to the rotors of the steam-driven engine of FIGS. 12-20.

As the rotor 280 approaches the one hundred and eighty degree position shown by FIG. 19, the notch 206 in the rotatable element 204 will be displaced from the outlet orifice 208, but the notch 222 in the rotatable element 220 will be uncovering the upper end of the outlet orifice 224. Consequently, steam will pass through the pipe 248, the rotor within the directional control housing 244, and the pipe 250 to the port 266;

and that steam will apply propulsive forces to the rotor 280, and thus will assist the steam, which is applied to the port 262 by valve 237, to cause the rotors 280 and 274 to continue to rotate in the clockwise direction.

As the rotors 274 and 280 move out of the positions shown by FIG. 19 and move toward the positions shown by FIG. 20, the rotatable element 204 will continue to block the outlet orifice 208, the notch 222 in the rotatable element 220 will expose the lower end of the outlet orifice 224, and valve 237 will supply steam to the port 262 via the directional control housing 234. This means that both of the rotors 274 and 280 will have steam applied to them to urge them to continue to rotate in the clockwise direction.

Sortly after the rotors 274 and 280 move past the positions shown by FIG. 20, the notch 222 in the rotatable element 220 will move out of register with the outlet orifice 224 and, thereupon, the flow of steam to the port 266 will be interrupted. However, steam will continue to flow to the port 262 via the valve 237. In addition, as the rotor 274 approaches its 180 position, the notch 206 in the rotatable element 204 will again uncover the upper end of the outlet orifice 208.

The steam-driven engine of FIGS. 12-20 is a two stage steam-driven engine; and the steam which exhausts from the cylindrical chamber 180 is subsequently supplied to the cylindrical chamber 182. Specifically, the steam which issues from the port 260 will pass through the pipe 241 to the directional control housing 234, will pass through the appropriate passage in the rotor of that directional control, will pass through the pipe 242 to the intermediate chamber 192, will pass through the pipe 246 to the inlet port of the valve housing 216 and will, if the notch 222 uncovers any part of the outlet orifice 224, pass from the outlet port 226 of that valve housing to the port 266 via pipe 248, directional control housing 244 and pipe 250. The steam which issues from the port 260 of the cylindrical chamber will be under a pressure that is substantially below that of the steam which enters the port 262 of that cylindrical chamber; but, where the pressure on the steam that is supplied to the port 262 is high enough, the pressure on the steam which issues from the port 260 is sufficiently high to be able to apply substantial propulsive forces to the rotor 280.

Steam will issue from the port 260 and will pass to the intermediate chamber 192 almost continuously whenever the shaft 282 is rotating in the clockwise direction; but steam will be able to issue from that intermediate chamber only when the notch 222 in the rotatable element 220 is in register with some part ofthe outlet orifice 224. Because that notch is in register with some part of that outlet orifice for only about one-third of each half-revolution of the shaft 282, the pressure within the intermediate chamber 192 will recurrently rise and fall. However, the volumetric capacity of that intermediate chamber is great enough to enable that intermediate chambe to easily accommodate all of the steam which could issue from the chamber 180 during any half-revolution of the shaft 282; and hence that intermediate chamber permits the pressure at the port 260 ofchamber 180 to drop well below the pressure at the port 262. Consequently, even though the steam which exits through the port 260 will periodically be kept from entering the chamber 182, the peak pressure on that steam will be below, and the average pressure on that steam will be well below, the pressure on the steam which is supplied to the port 262. The resulting pressure differential between the high pressure and low pressure ports of the chamber 180 enables the rotor 274 to apply substantial amounts of' force to the shaft 282.

If it becomes desirable to increase the pressure on the steam which the intermediate chamber 192 supplies to the port 266 via the valve housing 216 and the directional control housing 244, heat can be applied to that steam while that steam is in that intermediate chamber. That heat can be applied to that steam by disposing heat-exchanging pipes or tubes within the intermediate chamber 192, and then passing the products of combustion from the boiler through those pipes or tubes. The application of such heat to the steam within the intermediate chamber 192 would, of course, decrease the average pressure drop across the chamber 180; but it would materially increase the average pressure on the steam which was supplied to the port 266. The two stage steam-driven engine of FIGS. 12-20 can be operated by steam at different pressure; but it will usually be desirable to maintain a pressure of between one hundred and five hundred pounds per square inch on the steam which is supplied to the pipe 236.

As the shaft of the two-stage steam-driven engine of FIGS. 12-20 approaches its desired speed, a governor. not shown, will coact with a throttling valve, not shown, to limit the volume of steam which is supplied to the pipe 236. Also, the valve 237 will be closed; and, thereafter, steam will be supplied to the cylindrical chamber 180 during only about one-third of each revolution of the rotor 204 within the valve housing 198, and thus during only about one-third of each half-revolution of the rotor 274. Similarly, steam will be supplied to the cylindrical chamber 182 by the intermediate chamber 192, via the valve housing 216 and the directional control housing 244, during only about one-third of each revolution of the rotatable element 220, and thus during only about one-third of each half-revolution of the rotor 280. However, during the remaining two-thirds of each half-revolution of the rotor 274, the steam which is located between the port 262 and the confronting face of that rotor will continue to expand, and thus will continue to apply propulsive forces to that rotor. Similarly, during two-thirds of each half-revolution of the rotor 280, the steam whch is located between the port 266 and the confronting face of that rotor will continue to expand, and thus will continue to apply propulsive forces to that rotor. By supplying steam to the cylindrical chambers 180 and 182 during only limited portions of the half-revolutions of the rotors in those chambers, the steam-driven engine of FIGS. 12-20 can provide very economical operation.

The numeral 232 denotes a valve which has one port thereof connected to the pipe 246 and to the port 223 of the valve housing 216, and which has the other port thereof connected to the pipe 248 and to the port 226 of that valve housing. The valve 232 will be closed whenever the steam-driven engine of FIGS. 12-20 is operated in the forward direction. However, that valve will be open whenever that steam-driven engine is operated in the reverse direction; so it can by-pass the valve housing 216 and thereby enable the pipes 246 and 248 to supply steam to the directional control housing 244 and thus to the port 264 while that steam-driven engine is being operated in the reverse direction. The valve 232 is needed because the notch 222, in the rotatable element 220 within the valve housing 216, is in lapping relation with the outlet orifice 224 for only a very short period of time after the rotor 280 moves out of the position shown by FIG. 19. Consequently, without the valve 232, insufficient amounts of steam would be introduced into the cylindrical chamber 182 as the rotor 280 moved out of its zero and 180 positions whenever that rotor was operating in the reverse direction.

To cause the steam-driven engine of FIGS. 12-20 to drive the shaft 282 in the opposite direction, the valve 232 will be opened and the lever 256 will be rotated approximately 90 in the clockwise direction in FIG. 14; and at that time, the rotors within the directional control housings 234 and 244 will shift into their reverse positions. Thereafter, steam will flow from the directional control housing 234 via pipe 241 to the port 260 of the cylindrical chamber 180, and that steam subsequently will exhaust from port 262 via pipe 240, that directional control housing and pipe 242 to the intermediate chamber 192. That steam then will pass via pipe 246, valve 232 and valve housing 216, and pipe 248 to the directional control housing 244, to the port 264 via pipe 252, through the chamber 182, to that directional control housing via port 266 and pipe 250, and then via pipe 254 to the condenser, not shown. During the starting of the steam engine of FIGS. 12-20 in the opposite direction, the valve 237 will be opened to supply steam to the port 260 throughout each halfrevolution of the rotor 274.

The steam which is supplied to the port 260 will urge the rotor 274 to rotate in the counterclockwise direction, and the steam which is supplied to the port 264 will urge the rotor 280 to rotate in the counterclockwise direction even after the shaft 282 has reached its desired speed, the valve 237 will be left open, at least in part, to supply steam to the port 264.

The distance between the axis of the shaft 282 and the geometric center of the inner surface of the annulus 184 of the cylindrical chamber 180 preferably is onefifth of the radius of that inner surface. Similarly, the distance between the axis of that shaft and the geometric center of the inner surface of the annulus 188 of the cylindrical chamber 182 preferable is one-fith of the radius of that inner surface. Where that is the case, the centers of the rotors 274 and 280 will follow arcuate paths, which are essentially circular paths, as those rotors rotate, respectively, within the cylindrical chambers 180 and 182. The essentially circular natures of the arcuate paths through which the centers of the rotors 274 and 280 move, as those rotors rotate, respectively, within the cylindrical chambers 180 and 182, minimize acceleration components and also minimize vibration during the rotation of those rotors.

It will be noted that the ports 260 and 262 are adjacent the opposite ends of the major axis of the rotor 274 whenever that rotor is in its zero or one hundred and eighty degree position. Similarly, it will be noted that the ports 264 and 266 are adjacent the opposite ends of the major axis of the rotor 280 whenever that rotor is in its zero or 180 position; and, further it will be noted that the ports 50 and 52 are adjacent the opposite ends of the major axis of the rotor whenever that rotor is in its zero or one hundred and eighty degree position. This is desirable because it means that the steam-driven engine of FIGS. 1-11 does not require an exhaust valve, and also means that the steam-driven engine of FIGS. 12-20 does not require an exhaust valve. Further, it means that those steam-driven engines can be reversed without any need of complicated reversing equipment.-

The metal seals 158, 159, 160,161,169 and 171 will be lubricated by the introduction of oil into the steam which is supplied to the chamber 40. Similarly, the inner surfaces of annulus 42 and of side plates 58 and 64 will be lubricated by the introduction of oil into the steam which is supplied to that chamber. That oil can be introduced into that steam by any of the commercially-available devices which are marketed for that purpose. Such devices also can be used to introduce oil into the steam which is supplied to the chamber and that oil will lubricate the metal apex seals and the outer arcuate metal seals of the rotors 274 and 280, and also will lubricate the inner surfaces of the chambers 180 and 182.

Where the steam-driven engines of FIGS. 1-11 and 12-20 are large in size, roller bearings will preferably be used to minimize the frictional forces between the rotors and the squarefaced sections of the shafts of those steam-driven engines. Those roller bearings could be mounted on those square-faced sections and could bear against the elongated slots in those rotors, or those roller bearings could be mounted at the inner faces of those elongated slots and could bear against those square-faced sections.

FIGS. l-ll show a single-stage, positivedisplacement, steam-driven engine, and FIGS. 12-20 show a two-stage, positive-displacement, steam-driven engine. However, the steam-driven engine of the present invention could be made with as many stages as desired; and, regardless of the number of stages, that steam-driven engine would have the positivedisplacement characteristic which is a very desirable characteristic of piston-type steam engines, but also would provide the direct conversion of steam energy to rotary motion which is a desirable characteristic of steam turbines.

Because each of the output shafts of the steam-driven engines of FIGS. 1-11 and 12-20 rotates only one half ofa revolution while the rotatable elements in the valve housings of those steam-driven engines rotate a full revolution, each of those steam-driven engines will provide a double action. As a result, that steam-driven engine provides an action which is comparable to the double-acting reciprocation of a piston-type steam engine.

If desired, a mechanical or electrical starting device could be mounted adjacent the shaft 70 to initiate rotation of that shaft when that shaft happens to be in a position wherein the moment arm which therotor 130 can apply to that shaft is minimal. Such a starting device can be of standard and usual design. Further, if desired, a mechanical or electrical starting device could be mounted adjacent the shaft 282 to initiate rotation of that shaft when that shaft happens to be in a position wherein the moment arm which the rotor 274 can apply to that shaft is minimal.

The sockets for the bolt and nut combinations 170 in FIG. 3 perform a dual function. First, those sockets enable the nuts and the heads of the bolts of those bolt and nut combinations to be spaced wholly inwardly of the inner surface of the annulus 42. Second, those sockets increase the effective volumetric capacity of the high-pressure side of the chamber 40; and that increase in volumetric capacity is desirable, because it increases the amount of steam which can be introduced into, and which can expand within, that high-pressure side.

The rotors 274 and 280 of the steam-driven engine of FIGS. 1220 have sockets, not shown, which are comparable to the sockets that are provided in FIG. 3 for the nut and bolt combinations 170. The sockets in the rotors 274 and 280 will perform treble functions that are comparable to the treble functions which the sockets in FIG. 3 perform.

Referring particularly to FIG. 21, the numeral 290 denotes a cylindrical segment which is similar to the cylindrical segment 132 of FIGS. 1-11. That cylindrical segment has an arcuate groove 304 which can be identical to the arcuate groove 150 in the cylindrical seg ment 132; and the arcuate groove 304 accommodates an arcuate metal seal 306 which can be identical to the arcuate metal seal 158. The cylindrical segment 290 differs from the cylindrical segment 132 in having notches 294 and 296 which are adjacent the opposite ends of, but which are contiguous with, a notch 292 that is comparable to the notch 146 at one end of the cylindrical segment 132. The notches 294 and 296 are the same depth as the notch 292.

The numeral 298 denotes an apex metal seal which generally resembles the apex metal seal 171 of the steam-driven engine shown in FIGS. 1-11; but the apex metal seal 298 differs from the apex metal seal 171 in being U-shaped in configuration. The arms of the apex metal seal 298 are spaced apart a distance which is slightly greater than the distance between the notches 294 and 296; and the ends of those arms normally are lodged within those notches. Those arms and those notches are dimensioned to enable the ends of those arms to be lodged within those notches whenever the rotor, of which the cylindrical segment 290 is a part, is disposed within the cylindrical chamber for which it is designed. The arms of the apex metal seal 298 define a large, generally-rectangular notch 300 in the inner edge of the metal apex seal 298; and that notch accommodates a bowed leaf spring 302 which is similar to, but shorter than, the bowed leaf spring 173.

The apex metal seal 298 will perform all of the functions of the apex metal seal 171 of the steam-driven engine of FIGS. 1-11. However, in addition, the apex metal seal 298 will coact with the portion of the cylindrical segment 290 that is intermediate the notches 294 and 296 and also with the corresponding portion of the cylindrical segment which is secured to the cylindrical segment 290 to define the rotor to limit end-wise shifting of that apex metal seal relative to that rotor. Each of the notches 294 and 296 and the notch 292 will have depth just slightly greater than one-half the thickness of the apex metal seal 298. Consequently, those notches will coact with the corresponding notches in the cylindrical segment, which will be secured to the cylindrical segment 290, to define slots in which the ends of the arms of that apex metal seal can easily move.

Although the various seals shown by the drawing will preferably be made of metal, one or more of those seals could be made of other materials. For example, one or more of those seals could be made of ceramic material or of carbon.

Although steam is the preferred propulsive fluid for the engines of FIGS. 111 and 12-20, other propulsive fluids could be used. For example, compressed air, compressed non-corrosive gases, non-corrosive heated vapors, and the like could be used as the propulsive fluids for those engines. Steam is the preferred propulsive fluid, because of its availability, low cost and expansion capability, and non-corrosive heated vapors are desirable because of their expansion capabilities. Compressed air is desirable because of its availability and low cost.

Whereas the drawing and accompanying description have shown and described two preferred embodiments of the present invention, it should be apparent to those skilled in the art that various changes may be made in the form of the invention without affecting the scope thereof.

What I claim is:

1. A positive-displacement fluid-driven engine which comprises a generally cylindrical chamber that has a generally cylindrical wall, a shaft which extends into said chamber, said shaft having the axis thereof eccentric of the center of said generally cylindrical chamber, a generally elliptical rotor which is disposed within and which is rotatable relative to said generally cylindrical chamber, said rotor having a major axis and having an elongated slot therein which is generaly parallel to said major axis, said slot accommodating said shaft and being longer than said shaft is wide so said rotor can reciprocate relative to said shaft as said rotor rotates within said generally cylindrical chamber, an inlet port for propulsive fluid in said generally cylindrical wall of said generally cylindrical chamber, an outlet port for spent propulsive fluid in said generally cylindrical wall of said generally cylindrical chamber, said rotor responding to the introduction of propulsive fluid through said inlet port to rotate within said generally cylindrical chamber while reciprocating relative to said shaft, seals that are mounted on and that rotate with said rotor and that provide sealing engagements with said generally cylindrical wall of said generally cylindrical chamber, one of said seals being located at one end of said major axis of said rotor and another of said seals being located at the opposite end of said major axis of said rotor, one portion of the periphery of said rotor confronting and being in its closest proximity to one portion of the internal surface of said generally cylindrical wall of said generally cylindrical chamber whenever said rotor is in its zero position, the opposite portion of said periphery of said rotor confronting and being in its closest proximity to said one portion of said internal surface of said generally cylindrical wall of said generally cylindrical chamber whenever said rotor is displaced one hundred and eighty degrees from its said zero position, said one end of said major axis of said rotor being adjacent said inlet port whenever said rotor is in its said zero position, said opposite end of said major axis of said rotor being adjacent said outlet port whenever said rotor is in its said zero position, and said seals and sealing engagements helping said rotor respond to the introduction of said propulsive fluid into said generally cylindrical chamber through said inlet port to rotate within said generally cylindrical chamber while reciprocating relative to said shaft, a second generally cylindrical chamber which is mounted adjacent the first said generally cylindrical chamber and which has a generally cylindrical wall, said shaft also extending into said second generally cylindrical chamber, a second generally elliptical rotor which is disposed within and which is rotatable relative to said second generally cylindrical chamber, said second rotor having a major axis and having an elongated slot therein which is generally parallel to said major axis, said slot accommodating said shaft and being longer than said shaft is wide so said second rotor can reciprocate relative to said shaft as said second rotor rotates within said second generally cylindrical chamber, a second inlet port for propulsive fluid in said generally cylindrical wall of said second generally cylindrical chamber, a second outlet port for spent propulsive fluid in said second generally cylindrical chamber, said second rotor responding to the introduction of propulsive fluid through said second inlet port to rotate within said second generally cylindrical chamber while reciprocating relative to said shaft, further seals that are mounted on and that rotate with said second rotor and that provide sealing engagements with said generally cylindrical wall of said second generally cylindrical chamber, one of said further seals being located at one end of said major axis of said second rotor and another of said further seals being located at the opposite end of said major axis of said second rotor, one portion of the periphery of said second rotor confronting and being in its closest proximity to one portion of the internal surface of said generally cylindrical wall of said second generally cylindrical chamber whenever said second rotor is in its zero position, the opposite portion of said periphery of said second rotor confronting and being in its closest proximity to said one portion of said internal surface of said generally cylindrical wall of said second generally cylindrical chamber whenever said second rotor is displaced one hundred and eighty degrees from its said zero position, said one end of said major axis of said second rotor being adjacent said second inlet port whenever said second rotor is in its zero position, said opposite end of said major axis of said second rotor being adjacent said second outlet port whenever said second rotor is in its said zero position, said further seals and said sealing engagements helping said second rotor respond to the introduction of said propulsive fluid into said second generally cylindrical chamber through said second inlet port to rotate within said second generally cylindrical chamber while reciprocating relative to said shaft, a valve which is connected to the first said inlet port and which has a rotatable member that rotates when said first said rotor rotates, a second valve which is connected to said second inlet port and which has a rotatable member that rotates when said second rotor rotates, the first said valve supplying said propulsive fluid to said first said inlet port during just a part of each revolution of the first said rotor, an intermediate chamber which has the inlet thereof continuously connected to said first said outlet port and which has the outlet thereof selectively connected to said second inlet port by said second valve, whereby said intermediate chamber is continuously connected to said first said outlet port and is selectively connected to said second inlet port, and said intermediate chamber receiving said spent propulsive fluid from said first said outlet port and selectively supplying said spent propulsive fluid to said second inlet port, whereby said second rotor can be driven by said spent propulsive fluid, said second valve supplying said spent propulsive fluid to said second inlet port during just a part of each revolu- 

1. A positive-displacement fluid-driven engine which comprises a generally cylindrical chamber that has a generally cylindrical wall, a shaft which extends into said chamber, said shaft having the axis thereof eccentric of the center of said generally cylindrical chamber, a generally elliptical rotor which is disposed within and which is rotatable relative to said generally cylindrical chamber, said rotor having a major axis and having an elongated slot therein which is generaly parallel to said major axis, said slot accommodating said shaft and being longer than said shaft is wide so said rotor can reciprocate relative to said shaft as said rotor rotates within said generally cylindrical chamber, an inlet port for propulsive fluid in said generally cylindrical wall of said generally cylindrical chamber, an outlet port for spent propulsive fluid in said generally cylindrical wall of said generally cylindrical chamber, said rotor responding to the introduction of propulsive fluid through said inlet port to rotate within said generally cylindrical chamber while reciprocating relative to said shaft, seals that are mounted on and that rotate with said rotor and that provide sealing engagements with said generally cylindrical wall of said generally cylindrical chamber, one of said seals being located at one end of said major axis of said rotor and another of said seals being located at the opposite end of said major axis of said rotor, one portion of the periphery of said rotor confronting and being in its closest proximity to one portion of the internal surface of said generally cylindrical wall of said generally cylindrical chamber whenever said rotor is in its zero position, the opposite portion of said periphery of said rotor confronting and being in its closest proximity to said one portion of said internal surface of said generally cylindrical wall of said generally cylindrical chamber whenever said rotor is displaced one hundred and eighty degrees from its said zero position, said one end of said major axis of said rotor being adjacent said inLet port whenever said rotor is in its said zero position, said opposite end of said major axis of said rotor being adjacent said outlet port whenever said rotor is in its said zero position, and said seals and sealing engagements helping said rotor respond to the introduction of said propulsive fluid into said generally cylindrical chamber through said inlet port to rotate within said generally cylindrical chamber while reciprocating relative to said shaft, a second generally cylindrical chamber which is mounted adjacent the first said generally cylindrical chamber and which has a generally cylindrical wall, said shaft also extending into said second generally cylindrical chamber, a second generally elliptical rotor which is disposed within and which is rotatable relative to said second generally cylindrical chamber, said second rotor having a major axis and having an elongated slot therein which is generally parallel to said major axis, said slot accommodating said shaft and being longer than said shaft is wide so said second rotor can reciprocate relative to said shaft as said second rotor rotates within said second generally cylindrical chamber, a second inlet port for propulsive fluid in said generally cylindrical wall of said second generally cylindrical chamber, a second outlet port for spent propulsive fluid in said second generally cylindrical chamber, said second rotor responding to the introduction of propulsive fluid through said second inlet port to rotate within said second generally cylindrical chamber while reciprocating relative to said shaft, further seals that are mounted on and that rotate with said second rotor and that provide sealing engagements with said generally cylindrical wall of said second generally cylindrical chamber, one of said further seals being located at one end of said major axis of said second rotor and another of said further seals being located at the opposite end of said major axis of said second rotor, one portion of the periphery of said second rotor confronting and being in its closest proximity to one portion of the internal surface of said generally cylindrical wall of said second generally cylindrical chamber whenever said second rotor is in its zero position, the opposite portion of said periphery of said second rotor confronting and being in its closest proximity to said one portion of said internal surface of said generally cylindrical wall of said second generally cylindrical chamber whenever said second rotor is displaced one hundred and eighty degrees from its said zero position, said one end of said major axis of said second rotor being adjacent said second inlet port whenever said second rotor is in its zero position, said opposite end of said major axis of said second rotor being adjacent said second outlet port whenever said second rotor is in its said zero position, said further seals and said sealing engagements helping said second rotor respond to the introduction of said propulsive fluid into said second generally cylindrical chamber through said second inlet port to rotate within said second generally cylindrical chamber while reciprocating relative to said shaft, a valve which is connected to the first said inlet port and which has a rotatable member that rotates when said first said rotor rotates, a second valve which is connected to said second inlet port and which has a rotatable member that rotates when said second rotor rotates, the first said valve supplying said propulsive fluid to said first said inlet port during just a part of each revolution of the first said rotor, an intermediate chamber which has the inlet thereof continuously connected to said first said outlet port and which has the outlet thereof selectively connected to said second inlet port by said second valve, whereby said intermediate chamber is continuously connected to said first said outlet port and is selectively connected to said second inlet port, and said intermediate chamber receiving said spent propulsive fluid from said first said outlEt port and selectively supplying said spent propulsive fluid to said second inlet port, whereby said second rotor can be driven by said spent propulsive fluid, said second valve supplying said spent propulsive fluid to said second inlet port during just a part of each revolution of said second rotor. 